1. Field of the Invention
The present invention relates to a stylus pen, and more particularly to a capacitive stylus pen available for manipulation of a capacitive touch screen.
2. Description of the Related Art
A stylus pen is a kind of tool for manipulating an electronic or communication device in which a touch screen is installed, such as a Personal Digital Assistant (PDA), a cellular phone, a palm Personal Computer (PC), etc. When a manipulating member, a so-called tip, formed at an end of the stylus pen contacts the touch screen, the electronic or communication device operates responsively, essentially enabling an input of user desired information to the electronic or communication device. In many related applications, icons or menus are displayed on the touch screen, and upon user's selection of a desired icon or menu with the stylus pen, the electronic or communication device performs a corresponding function associated with the icon or menu.
The continued growth and popularity of portable terminals for mobile communication, e.g., Smartphone's and other hand-held electronic devices, as well as the increased commercialization of multimedia services accessed using portable terminals has seen a commensurate increase in the demand for various display devices and the input devices for inputting data therethrough. To meet such growing demands, and the demands for rendering the portable terminals more compact and lightweight, touch screens are increasingly used to operate concurrently both as an input device and a display device.
Touch screens may be classified into resistive touch screens and capacitive touch screens. The resistive touch screen generates an input signal by sensing a position on the touch screen at which a user applies a touching force causing contact between two resistive screen layers. The capacitive touch screen generates an input signal by sensing a position on the touch screen at which a user applies a touch causing a change in detected capacitance from a micro-current flowing through a user's body, i.e., the user's finger. The capacitive touch screen, when compared to the resistive touch screen, provides a smoother manipulation feeling and action, e.g., scroll. For that matter, a capacitive touch screen allows for multi-touching contact and manipulation of various touch screen positions or points at the same time. Thus, the user may feel that a portable terminal using a capacitive touch screen is more elegant than a portable terminal using a resistive touch screen.
As resistive touch screens are responsive to an input signal from a user's manipulating force, they may be manipulated by use of other tools or body portions, such as a pen, a pencil, or a nail, as well as a finger. On the other hand, the capacitive touch screen operates by a human's micro-current, limiting manipulation using a general tool such as a pen or a pencil. This results in a need for a separate tool for manipulating the capacitive touch screen, such as a stylus pen, which is able to transfer the human's micro-current to the touch screen.
Moreover, with the combination of a multimedia function as well as a voice communication function in portable terminals, a need arises for the use of a wireless headset based on Near Field Communication (NFC), such as Bluetooth in such portable terminals.
The wireless headset, however, has to be carried together with the portable terminal, and the portable terminal having a touch screen mounted thereon has to be accompanied by a separate stylus pen. In order to realize a compact and convenient solution to these requirements, effort has been exerted to integrate the stylus pen and the wireless headset. However, as the stylus pen for manipulating the capacitive touch screen needs to be made of a conductive material to transfer the human's micro-current to the touch screen, such conductive material construction tends to hinder transmission and reception functions of the wireless headset. In an effort to secure an installation space of the wireless headset, a portion made of synthetic resin as well as a portion made of the conductive material are added to the stylus pen. But these added portions have the effect of increasing the diameter or length of the stylus pen thus hindering miniaturization.